Acoustic imaging includes a variety of techniques that are used in the energy industry to measure or estimate characteristics of earth formations. For example, ultrasonic imaging tools can be deployed in a borehole and used to obtain information regarding formation characteristics such as lithology and fracture configurations. Such tools can also be used to determine casing conditions. Downhole conditions require that imaging tool components be able to operate effectively in high temperature conditions. The ability to effectively direct an acoustic beam to a desired location of a formation can be effected by the harshness of a downhole environment and changing conditions downhole.